Storage is the holding of waste for a temporary period of time prior to the waste being treated, disposed, or stored elsewhere.
Hazardous waste is commonly stored prior to treatment or disposal, and must be stored in containers, tanks, containment buildings, drip pads, waste piles, or surface impoundments that comply with the RCRA regulations.
Methods of Waste Storage
Containers – A hazardous waste container is any portable device in which a hazardous waste is stored, transported, treated, disposed, or otherwise handled. The most common hazardous waste container is the 55-gallon drum. Other examples of containers are tanker trucks, railroad cars, buckets, bags, and even test tubes.
Tanks – Tanks are stationary devices constructed of non-earthen materials used to store or treat hazardous waste. Tanks can be open-topped or completely enclosed and are constructed of a wide variety of materials including steel, plastic, fiberglass, and concrete.
Drip Pads – A drip pad is a wood drying structure used by the pressure-treated wood industry to collect excess wood preservative drippage. Drip pads are constructed of non-earthen materials with a curbed, free-draining base that is designed to convey wood preservative drippage to a collection system for proper management
Containment Buildings – Containment buildings are completely enclosed, self-supporting structures (i.e., they have four walls, a roof, and a floor) used to store or treat non-containerized hazardous waste.
Waste Piles – A waste pile is an open, uncontained pile used for treating or storing waste. Hazardous waste waste piles must be placed on top of a double liner system to ensure leachate from the waste does not contaminate surface or ground water supplies.
Surface Impoundments – A surface impoundment is a natural topographical depression, man-made excavation, or diked area such as a holding pond, storage pit, or settling lagoon. Surface impoundments are formed primarily of earthen materials and are lined with synthetic plastic liners to prevent liquids from escaping.
What is nuclear fuel?
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials.
Most nuclear fuels contain heavy metal fissile elements that can be made to undergo a nuclear fissionchain reaction in a nuclear reactor. The most common fissile nuclear fuels are Uranium 235 (235U) and Plutonium 239 (239Pu). The actions of mining, refining, purifying, using, and ultimately disposing of these elements together make up the nuclear fuel cycle.
This is where we will post all the research/ideas done thus far
Darya's Research Short-term storage:
Fuel Rod Storage Pools
wet storage method
spent fuel rods from a nuclear reactor are the most radioactive of all nuclear waste
no permanent storage site of spent fuel rods now
When the spent fuel rods are removed from the reactor core, they are extremely hot and must be cooled down. Most nuclear power plants have a temporary storage pool next to the reactor. The spent rods are placed in the pool, where they can cool down. The pool is not filled with ordinary water but with boric acid, which helps to absorb some of the radiation given off by the radioactive nuclei inside the spent rods.
The spent fuel rods are supposed to stay in the pool for only about 6 months, but, because there is no permanent storage site, they often stay there for years.
Causes major problems along the way as pools fill: if the rods are placed too close together, the remaining nuclear fuel could go critical, starting a nuclear chain reaction.
Thus, the rods must be monitored and it is very important that the pools do not become too crowded. Also, as an additional safety measure, neutron-absorbing materials similar to those used in control rods are placed among the fuel rods.
permanent disposal of the spend fuel is gaining more and more importance as the pools become more and more crowded.
Dry Cask Storage Containers
developed as a result of overcrowding of pools.
dry storage method.
waste is taken and put in reinforced casks or entombed in concrete bunkers
this is done after the waste has spend around 5 years cooling in a pool
casks are usually located close to the reactor site
In Canada, “high-level nuclear waste” refers to used nuclear reactor fuel (highly radioactive substance, particularly within a few years of its discharge from the reactor core)
Radiation emitted by both the fission fragments (what the uranium atoms become after they split roughly in half) built up over the duration of the fuel’s residence in the reactor core, and the higher actinides (what the uranium atoms become after they absorb a neutron and fail to split).
Short-term:
Used fuel from each reactor is stored on-site in deep water pools used for cooling and shielding. There are about two million used fuel bundles (0.5 m long, weighing 20 kg each) in Canada, which would fill a soccer field to the height of a player. Once a few years have passed, the used fuel may be moved to above-ground dry storage in concrete canisters, with passive cooling provided by air flow.
The cooling, by either water or air flow, is required because used fuel contains a small inventory of fission products (created by the fission of less than 2% of the original uranium inventory) that continue to emit energy as they radioactively decay. In fact, immediately upon removal from the reactor core, a used CANDU fuel bundle generates about 10% of the heat that it produced in the core, but this figure drops to about 1% only a day after removal, and less than 0.1% after a year has passed. The average heat generation of a fuel bundle at this point (one year) is about 100 W -- comparable to a household lightbulb.
The radiation accounting for this heating creates a simultaneous need for shielding. About three metres of water are sufficient to absorb the radiation emitted initially by the used fuel, while in the dry-storage phase about a metre of concrete suffices.
Also has long-term management, look it up
Source: http://www.nuclearfaq.ca/cnf_sectionE.htm
Curtis: (expanding from previous group member's research) Aside from the storage of nuclear fuel rods, scientists can also extract some of the components to reduce the amount of waste by recycling. This process is called "reprocessing":
-Fissile materials are extracted and recycled
-reprocessing technology is used along with fast neutron reactors to burn long-lived actinides
-plutonium can be recycled and used in MOX fuels
-MOX (Mixed Oxide Fuel) can be used in certain nuclear power plants; somewhat controversial, was used in the japan power plant that undergone somewhat of a meltdown after the tsunami
-small amounts of uranium can also be recovered and used once more in fuel rods
There are two main ways to managing used fuel rods as previously said:
-nuclear ponds
-90% of waste are stored in ponds
-wastes can be taken out of ponds after 6 months and stored above ground for cooling
-stainless steel cylinders (dry cask)
-contains wastes which have been removed from ponds
Both methods are described as short term because a lot of the waste can be recycled and reused after the rods cool and the energy level released dies down. The long term storage management method is for wastes that cannot be recycled.
source: http://world-nuclear.org/info/inf04.html
Adv: Leading way of storing nuclear fuel rods and kept for recycling for another use
Disadv: Takes up space among the power plants; must be monitored constantly
Meredith: Short Term Waste Management Research. Short Term Nuclear Waste Storage
Method:
Short-term storage can reduce the radioactivity of the nuclear waste by a 100 times. It is also worth noting that the half-life of certain radioactive wastes can be in the range of 500,000 years or more. Spent Fuel Pools: Spent Fuel rods are the fuel elements used at a nuclear plant, but are no longer capable of economically sustaining a nuclear reaction. The rods in the nuclear reactor are replaced about every 12 -18 months, while the spent fuel rods are stored in the pool up to 5 years. (But according to mathematical calculations, have the capacity to be stored in said pool for up to 60). When Fuel Rods are under normally 40 feet (12 meters) of water, which provides adequate shielding form the radiation for anyone near the pool. The main purpose of submerging the used fuel rods is to both shield the radiation and cool down the rods. The average heat generation of a fuel bundle at this point (one year) is about 100 W -- comparable to a household light bulb.
Safety Procedures: The steel and concrete pools are designed to be 40 feet deep (12 m), 35 feet wide (10.7 m), and 40 feet long (12 m). Although individual spent fuel pools specifications vary, one common feature they all share is that they are outside the containment structure that holds the reactor pressure vessel. They are designed to with stand seismic activity. They are designed without drains in their sides or floor so water cannot drain as a result of damage to piping or cooling systems. The placements of the fuel rods are often in a “checkerboard” arrangement as a safety precaution. The newest fuel assemblies are placed with the older, cooler assemblies. This way the cooler assemblies with draw the heat away from the hotter ones. Problems with solution: After 9/11 terrorist attacks are a concern for the spent fuel pools, which were built to within stand, to a degree, natural disasters, but not man made ones. If the spent fuel pools manage to get damaged by natural disasters (Japan), human error, or terrorist attack, that could either cause a leak from the pool, or damage the cooling system. If the water level is low enough, either due to the leakage, or the evaporation (caused by the lack of cooling systems), the fuel rods could become exposed. This would mean that the fuel rods would then be exposed, releasing tons of radioactivity. Cost: In the United States, 35.8 billion dollars has been budgets towards nuclear waste management, with 10.8 billion dollars having been spent so far. The NWMO (Nuclear Waste Management Organization) estimates it will cost somewhere in the range of $16 billion to $24 billion to site, build and maintain a central storage facility big enough and safe enough to handle the bundles. Some of the money will be used to store bundles at reactor sites before they are moved. Reference: (http://www.nei.org/resourcesandstats/nuclear_statistics/costs/) Reference: (http://www.cbc.ca/news/canada/story/2009/08/18/f-nuclear-waste-storage.html) Reference: (http://www.nrc.gov/waste/spent-fuel-storage/faqs.html#19)
Dry Cast Storage: Most of the world’s spent fuel is still be stored in spent fuel pools. It is after all a tried and tested technology. However there has been a recent trend in which countries are starting to use more dry storage as a effective means of storing nuclear waste both short and long term. Dry cask’s are typically steel, bolted closed into a leak tight container. Then additional steel, concrete and other materials surround the containers. These materials will provide shielding for radioactivity from the workers. Once spent fuel rods have been submerged in the spent fuel pools for a least a year, they can be transferred to the dry cask storage. Once inside, they are also surrounded by an inert gas. The Fuel rods are kept cool by natural airflow. Advantages over Spent Fuel Pools: Less spent fuel is at risk in an attack or accident scenario. An attack on dry cask storage would put at most a few of the dry cask containers at risk. An attack on the spent fuel pool would put all of the spent fuel at risk. The potential consequences of an accident or terrorist attack would be far less when involving dry cask containers then spent fuel pools. This is due to the fact that the there are less spent fuel cells within the dry cask, there is less potential for radioactive material to be released. Less Fuel in the pools, makes easier for the Fuel to cool down. If more of the spent fuel rods were stored in the dry casks, then there would be more space wihin the pool. This would mean that there would be more water flow between the spent fuel rods, which makes them easier to cool. Problems with Solution: Here’s a diagram of a standard dry cask container: http://www.nrc.gov/images/waste/spent-fuel-storage/dry-cask-storage/dry-cask.gif
Canadian Nuclear Waste Management: There are about two million used fuel bundles in Canada. (That would fill a soccer field, the rods the height of an average male player. orA CANDU fuel assembly is approximately 0.5 meters long. Stacked like cordwood, all of Canada's used nuclear fuel could fit into six hockey rinks.)
The average heat generation of a fuel bundle at this point (one year) is about 100 W -- comparable to a household light bulb.
Shirley’s Research
Japan earthquake:
Besides killing thousands of people via the earthquake and the later tsunami, the people of Japan now has to deal with the aftermath of the explosion of the nuclear power plant.
Depression, suicide, alienation, betrayal and guilt
Under Japan’s “Road Map,” expected to have cleaned up the spills in 6 months [next year Jan.]
"After the incident with Fukushima Daiichi nuclear power plant, I think it is a very good idea that each country conduct their own stress test to verify the safety of their nuclear power plant," Amano said after the meeting with Japan’s PM, as cited by the Associated Press. [taken directly, need paraphrase]
Dr. Robert Jacobs, a professor of nuclear history at Hiroshima states that “the plants will be leeching radiation for at least one more year, possible several more years, and it is turning up increasingly in various parts of the food-supply in far-flung regions.” [rephrase more]
Slower progress in the building of new nuclear plants because of the Japan earthquake
However, will still continue because of increasing usage of energy
There will be supposedly better nuclear plants to be built where the plants will use less energy to run, therefore costing less, and not release radioactive substance into the air in case of meltdown
But whether nuclear plants are safe is still an ongoing issue
Some suspension of projects to inspect the old ones
Japan kept their spent cells in temporary storages
If fuel cells were to be exposed to the air for hours, the casing would start to burn and the materials that is made out takes a long time for a fire to be put out
What is storage waste?
Storage is the holding of waste for a temporary period of time prior to the waste being treated, disposed, or stored elsewhere.
Hazardous waste is commonly stored prior to treatment or disposal, and must be stored in containers, tanks, containment buildings, drip pads, waste piles, or surface impoundments that comply with the RCRA regulations.
Methods of Waste Storage
Containers – A hazardous waste container is any portable device in which a hazardous waste is stored, transported, treated, disposed, or otherwise handled. The most common hazardous waste container is the 55-gallon drum. Other examples of containers are tanker trucks, railroad cars, buckets, bags, and even test tubes.
Tanks – Tanks are stationary devices constructed of non-earthen materials used to store or treat hazardous waste. Tanks can be open-topped or completely enclosed and are constructed of a wide variety of materials including steel, plastic, fiberglass, and concrete.
Drip Pads – A drip pad is a wood drying structure used by the pressure-treated wood industry to collect excess wood preservative drippage. Drip pads are constructed of non-earthen materials with a curbed, free-draining base that is designed to convey wood preservative drippage to a collection system for proper management
Containment Buildings – Containment buildings are completely enclosed, self-supporting structures (i.e., they have four walls, a roof, and a floor) used to store or treat non-containerized hazardous waste.
Waste Piles – A waste pile is an open, uncontained pile used for treating or storing waste. Hazardous waste waste piles must be placed on top of a double liner system to ensure leachate from the waste does not contaminate surface or ground water supplies.
Surface Impoundments – A surface impoundment is a natural topographical depression, man-made excavation, or diked area such as a holding pond, storage pit, or settling lagoon. Surface impoundments are formed primarily of earthen materials and are lined with synthetic plastic liners to prevent liquids from escaping.
What is nuclear fuel?
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials.
Most nuclear fuels contain heavy metal fissile elements that can be made to undergo a nuclear fission chain reaction in a nuclear reactor. The most common fissile nuclear fuels are Uranium 235 (235U) and Plutonium 239 (239Pu). The actions of mining, refining, purifying, using, and ultimately disposing of these elements together make up the nuclear fuel cycle.
Not all nuclear fuels are used in fission reactors. Plutonium-238 and some other elements are used to produce small amounts of nuclear power by radioactive decay in radioisotope thermoelectric generators and other atomic batteries. Light nuclides such as 3H (tritium) are used as fuel for nuclear fusion.
This is where we will post all the research/ideas done thus far
Darya's Research
Short-term storage:
Source: http://library.thinkquest.org/17940/texts/nuclear_waste_storage/nuclear_waste_storage.html
Management of high-level nuclear waste in Canada
Source: http://www.nuclearfaq.ca/cnf_sectionE.htm
Curtis: (expanding from previous group member's research)
Aside from the storage of nuclear fuel rods, scientists can also extract some of the components to reduce the amount of waste by recycling. This process is called "reprocessing":
-Fissile materials are extracted and recycled
-reprocessing technology is used along with fast neutron reactors to burn long-lived actinides
-plutonium can be recycled and used in MOX fuels
-MOX (Mixed Oxide Fuel) can be used in certain nuclear power plants; somewhat controversial, was used in the japan power plant that undergone somewhat of a meltdown after the tsunami
-small amounts of uranium can also be recovered and used once more in fuel rods
Source: http://world-nuclear.org/info/inf69.html
There are two main ways to managing used fuel rods as previously said:
-nuclear ponds
-90% of waste are stored in ponds
-wastes can be taken out of ponds after 6 months and stored above ground for cooling
-stainless steel cylinders (dry cask)
-contains wastes which have been removed from ponds
Both methods are described as short term because a lot of the waste can be recycled and reused after the rods cool and the energy level released dies down. The long term storage management method is for wastes that cannot be recycled.
source: http://world-nuclear.org/info/inf04.html
Adv: Leading way of storing nuclear fuel rods and kept for recycling for another use
Disadv: Takes up space among the power plants; must be monitored constantly
Meredith: Short Term Waste Management Research.
Short Term Nuclear Waste Storage
Method:
Short-term storage can reduce the radioactivity of the nuclear waste by a 100 times. It is also worth noting that the half-life of certain radioactive wastes can be in the range of 500,000 years or more.
Spent Fuel Pools:
Spent Fuel rods are the fuel elements used at a nuclear plant, but are no longer capable of economically sustaining a nuclear reaction. The rods in the nuclear reactor are replaced about every 12 -18 months, while the spent fuel rods are stored in the pool up to 5 years. (But according to mathematical calculations, have the capacity to be stored in said pool for up to 60).
When Fuel Rods are under normally 40 feet (12 meters) of water, which provides adequate shielding form the radiation for anyone near the pool. The main purpose of submerging the used fuel rods is to both shield the radiation and cool down the rods. The average heat generation of a fuel bundle at this point (one year) is about 100 W -- comparable to a household light bulb.
Safety Procedures:
The steel and concrete pools are designed to be 40 feet deep (12 m), 35 feet wide (10.7 m), and 40 feet long (12 m). Although individual spent fuel pools specifications vary, one common feature they all share is that they are outside the containment structure that holds the reactor pressure vessel. They are designed to with stand seismic activity.
They are designed without drains in their sides or floor so water cannot drain as a result of damage to piping or cooling systems.
The placements of the fuel rods are often in a “checkerboard” arrangement as a safety precaution. The newest fuel assemblies are placed with the older, cooler assemblies. This way the cooler assemblies with draw the heat away from the hotter ones.
Problems with solution:
After 9/11 terrorist attacks are a concern for the spent fuel pools, which were built to within stand, to a degree, natural disasters, but not man made ones.
If the spent fuel pools manage to get damaged by natural disasters (Japan), human error, or terrorist attack, that could either cause a leak from the pool, or damage the cooling system. If the water level is low enough, either due to the leakage, or the evaporation (caused by the lack of cooling systems), the fuel rods could become exposed. This would mean that the fuel rods would then be exposed, releasing tons of radioactivity.
Cost:
In the United States, 35.8 billion dollars has been budgets towards nuclear waste management, with 10.8 billion dollars having been spent so far.
The NWMO (Nuclear Waste Management Organization) estimates it will cost somewhere in the range of $16 billion to $24 billion to site, build and maintain a central storage facility big enough and safe enough to handle the bundles. Some of the money will be used to store bundles at reactor sites before they are moved.
Reference: (http://www.nei.org/resourcesandstats/nuclear_statistics/costs/)
Reference: (http://www.cbc.ca/news/canada/story/2009/08/18/f-nuclear-waste-storage.html)
Reference: (http://www.nrc.gov/waste/spent-fuel-storage/faqs.html#19)
Dry Cast Storage:
Most of the world’s spent fuel is still be stored in spent fuel pools. It is after all a tried and tested technology. However there has been a recent trend in which countries are starting to use more dry storage as a effective means of storing nuclear waste both short and long term.
Dry cask’s are typically steel, bolted closed into a leak tight container. Then additional steel, concrete and other materials surround the containers. These materials will provide shielding for radioactivity from the workers.
Once spent fuel rods have been submerged in the spent fuel pools for a least a year, they can be transferred to the dry cask storage. Once inside, they are also surrounded by an inert gas.
The Fuel rods are kept cool by natural airflow.
Advantages over Spent Fuel Pools:
Less spent fuel is at risk in an attack or accident scenario. An attack on dry cask storage would put at most a few of the dry cask containers at risk. An attack on the spent fuel pool would put all of the spent fuel at risk.
The potential consequences of an accident or terrorist attack would be far less when involving dry cask containers then spent fuel pools. This is due to the fact that the there are less spent fuel cells within the dry cask, there is less potential for radioactive material to be released.
Less Fuel in the pools, makes easier for the Fuel to cool down. If more of the spent fuel rods were stored in the dry casks, then there would be more space wihin the pool. This would mean that there would be more water flow between the spent fuel rods, which makes them easier to cool.
Problems with Solution:
Here’s a diagram of a standard dry cask container:
http://www.nrc.gov/images/waste/spent-fuel-storage/dry-cask-storage/dry-cask.gif
Canadian Nuclear Waste Management:
There are about two million used fuel bundles in Canada. (That would fill a soccer field, the rods the height of an average male player. orA CANDU fuel assembly is approximately 0.5 meters long. Stacked like cordwood, all of Canada's used nuclear fuel could fit into six hockey rinks.)
The average heat generation of a fuel bundle at this point (one year) is about 100 W -- comparable to a household light bulb.
Shirley’s Research
Japan earthquake:
http://rt.com/news/suicide-japan-disaster-farmers/
http://rt.com/news/fukushima-crisis-plant-nuclear/
http://www.bbc.co.uk/news/world-asia-pacific-12911190
http://www.bbc.co.uk/news/world-asia-pacific-12726591
http://www.bbc.co.uk/news/business-12747734
http://rt.com/news/chernobyl-exclusion-zone-population/
http://www.bloomberg.com/news/2011-08-14/japan-prepares-for-its-first-import-of-radioactive-waste-since-earthquake.html
http://www.nytimes.com/2011/03/18/world/asia/18spent.html?pagewanted=all